KR20160098523A - Method for producing metal oxide film and metal oxide film - Google Patents

Abstract

An object of the present invention is to provide a method for producing a metal oxide film which is capable of producing a metal oxide film having good film characteristics (low resistance) at low cost. In the present invention, the solution 5 containing zinc (A) is misted, and the mist 5 is sprayed onto the substrate 1 under a non-vacuum to form a metal A step of forming the oxide film 10 and a step of lowering the resistance of the metal oxide film 10 by irradiating the metal oxide film 10 with ultraviolet rays 13. [ The step (B) includes a step of determining the wavelength of the ultraviolet ray 13 to be irradiated in accordance with the film thickness of the metal oxide film 10, (B-2) And a step of irradiating the metal oxide film (10) with the ultraviolet ray (13) having the determined wavelength.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a metal oxide film,

INDUSTRIAL APPLICABILITY The present invention can be applied to a method for producing a metal oxide film and a method for manufacturing a metal oxide film used in, for example, solar cells and electronic devices.

As a method of forming a metal oxide film used in a solar cell, an electronic device, or the like, for example, MOCVD (Metal Organic Chemical Vapor Deposition) method or a sputtering method using a vacuum is employed. The metal oxide film produced by the method for producing the metal oxide film has excellent film properties.

For example, when a transparent conductive film is produced by the above-described method for producing a metal oxide film, the resistance of the transparent conductive film is low, and even if the transparent conductive film after the production is subjected to heat treatment, Do not rise.

As a prior art relating to the film formation of a zinc oxide film by the MOCVD method, for example, Patent Document 1 exists. As a prior art relating to the formation of a zinc oxide film by a sputtering method, for example, Patent Document 2 exists.

Japanese Patent Application Laid-Open No. 2011-124330 Japanese Patent Application Laid-Open No. 9-45140

However, in the MOCVD method, high cost is required to realize the method, and it is necessary to use an unstable material in the air, which is inferior in convenience.

When a thin film is intentionally doped with an impurity into a film by a sputtering method, a material containing a dopant in a predetermined concentration of a base material is generally used as a target material. For this reason, the dopant concentration in the thin film obtained by film formation using the same target material is limited to the dopant concentration in the target material. Therefore, for example, when forming a thin film having a different dopant concentration, a target material corresponding to each concentration is required, and it is difficult to derive the film forming conditions. Further, when a laminated structure in which the doping concentration is changed by a sputtering method is required, a plurality of devices are required, which causes an increase in the device cost.

Therefore, an object of the present invention is to provide a method for producing a metal oxide film, which is capable of producing a metal oxide film having good film characteristics (low resistance) at low cost. It is another object of the present invention to provide a method for manufacturing a metal oxide film which can realize a low resistance of a metal oxide film more efficiently. It is also an object of the present invention to provide a metal oxide film formed by the method for manufacturing a metal oxide film.

In order to achieve the above object, a method for producing a metal oxide film according to the present invention comprises the steps of (A) forming a mist containing a solution containing zinc and spraying the mist-prepared solution onto a substrate in a non- (B) a step of lowering the resistance of the metal oxide film by irradiating the metal oxide film with ultraviolet light, wherein the step (B) includes a step of forming a metal oxide film on the substrate, (B-1) a step of determining the wavelength of the ultraviolet ray to be irradiated in accordance with the film thickness of the metal oxide film; and (B-2) a step of irradiating the ultraviolet ray having the wavelength determined in the step On the surface of the substrate.

The method for producing a metal oxide film according to claim 1 of the present invention comprises the steps of (A) forming a mist containing a solution containing zinc and spraying the solution obtained in the misted condition onto the substrate under non-vacuum conditions, (B-1) forming a metal oxide film on a substrate; and (B) lowering the resistance of the metal oxide film by irradiating the metal oxide film with ultraviolet light. (B-2) a step of irradiating the ultraviolet ray having a wavelength determined in the step (B-1) to the metal oxide film in accordance with the film thickness of the metal oxide film; Respectively.

Therefore, even if the metal oxide film is formed on the substrate under non-vacuum and the resistance of the metal oxide film thus formed is increased, the resistance of the metal oxide film can be lowered by the subsequent irradiation with ultraviolet rays The resistance of the metal oxide film formed under the non-vacuum can be reduced to the same level as the resistance of the metal oxide film). Further, in the present invention, since it is not necessary to employ a device for maintaining the vacuum state by making a vacuum state as the film forming apparatus, it is possible to reduce the cost and improve the convenience.

Further, in the present invention, the wavelength of the ultraviolet ray to be irradiated is determined according to the film thickness of the metal oxide film. Therefore, it is possible to irradiate the metal oxide film with an ultraviolet ray having a wavelength capable of improving the efficiency of lowering the resistance (shortening and decreasing the resistivity in a short time) in response to the film thickness of the metal oxide film.

The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a configuration diagram of a film forming apparatus for explaining a method of forming a metal oxide film according to the present invention. FIG.
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a metal oxide film.
3 is an experimental data for explaining the effect of the method for producing a metal oxide film according to the present invention.
4 is an experimental data for explaining the effect of the method for producing a metal oxide film according to the present invention.
5 is a table of experimental data for explaining the effect of the method for producing a metal oxide film according to the present invention.
6 is an experimental data for explaining the effect of the method for producing a metal oxide film according to the present invention.
7 is an experimental data for explaining the effect of the method for producing a metal oxide film according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments thereof.

≪ Embodiment >

In the method for producing a metal oxide film according to the present invention, film formation is performed under non-vacuum (atmospheric pressure). Specifically, a method of manufacturing a metal oxide film according to the present invention will be described using a manufacturing apparatus (film forming apparatus) shown in Fig.

First, a solution 5 containing at least zinc is prepared. Here, as the solvent of the solution (5), an organic solvent such as ether or alcohol is employed. The thus prepared solution 5 is filled in the container 3A.

On the other hand, water (H ₂ O) is employed as the oxidizing source (oxidizing source) 6, and the oxidizing source 6 is filled in the container 3B. In addition to water, oxygen, ozone, hydrogen peroxide, N ₂ O and NO ₂ can be used as the oxidizing source 6, but water is preferable from the viewpoint of low cost and ease of handling (hereinafter referred to as oxidizing source 6) This water is called). When a dopant-containing metal oxide film is formed, a dopant is added to water as the oxidizing source 6, or a dopant is added to the solution 5 containing zinc, depending on the solubility and reactivity of the dopant do. Alternatively, a separate container (not shown in Fig. 1) may be provided, and a dopant may be supplied to the substrate 1 by a separate system.

Next, the solution (5) and the oxidizing source (6) are respectively misted. A atomizer (atomizer) 4A is provided at the bottom of the vessel 3A and a atomizer 4B is provided at the bottom of the vessel 3B. The solution 5 in the vessel 3A is misted by the atomizer 4A and the oxidizing source 6 in the vessel 3B is misted by the atomizer 4B.

The misted solution 5 is supplied to the nozzle 8 through the path L1 and the misted oxidizing source 6 is supplied to the nozzle 8 through the path L2. Here, as shown in Fig. 1, the path L1 and the path L2 are separate paths.

On the other hand, as shown in Fig. 1, the substrate 1 is placed on the heater 2. Here, the substrate 1 is placed under a non-vacuum (atmospheric pressure). The substrate 1 placed under the non-vacuum (atmospheric pressure) is sprayed through the nozzle 8 with the misted solution 5 and the mist oxidized circle 6, respectively. Here, at the time of spraying, the substrate 1 is heated to, for example, about 200 캜 by the heater 2.

With the above process, a metal oxide film (zinc oxide film as a transparent conductive film) having a predetermined film thickness is formed on the substrate 1 placed under a non-vacuum (atmospheric pressure). Further, by adjusting the supply amount of the solution (5) or the like, the film thickness of the metal oxide film can be adjusted to a desired thickness.

However, the metal oxide film formed under non-vacuum (atmospheric pressure) has higher resistance than the metal oxide film formed under vacuum such as the sputtering method. Thus, in the method for producing a metal oxide film according to the present invention, the following process is performed.

2, the entire surface of the main surface of the metal oxide film 10 formed on the substrate 1 is irradiated with ultraviolet light (ultraviolet light) 12) or the like is used to irradiate the ultraviolet ray 13. The resistance (resistivity) of the metal oxide film 10 can be lowered by the irradiation of the ultraviolet ray 13.

In the method for producing a metal oxide film according to the present invention, the wavelength of the ultraviolet ray 13 to be irradiated is determined in accordance with the film thickness of the metal oxide film 10 in the ultraviolet ray irradiation treatment. Then, the ultraviolet ray 13 having the determined wavelength is irradiated onto the entire surface of the main surface of the metal oxide film 10.

The method of determining the wavelength of the ultraviolet ray 13 to be irradiated will be described in detail using the following specific experimental example.

3 and 4 are experimental data showing the relation between the resistivity of the metal oxide film and ultraviolet irradiation for each of a plurality of film thicknesses of the metal oxide film (zinc oxide film). Here, FIG. 4 selects data on the film thickness of the metal oxide film of an arbitrary film thickness from the experimental data shown in FIG.

As shown in the abscissa of Figs. 3 and 4, the first metal oxide film formed under the non-vacuum is subjected to the first heat treatment for 20 minutes, and the metal oxide film after the first heat treatment is subjected to heat treatment at a center wavelength of 254 nm Ultraviolet rays were irradiated for 60 minutes and then the metal oxide film was irradiated with ultraviolet rays having a center wavelength of 365 nm for 60 minutes and thereafter the metal oxide film was subjected to a second heat treatment for 20 minutes, The metal oxide film after the subsequent heat treatment was irradiated with ultraviolet ray having a center wavelength of 365 nm for 60 minutes and then irradiated with ultraviolet ray having a center wavelength of 254 nm for the metal oxide film for 60 minutes.

As shown in Figs. 3 and 4, the vertical axis indicates the resistivity (? 占) m) of the metal oxide film. 3 shows data on a metal oxide film of a film thickness (259 nm, 303 nm, 334 nm, 374 nm, 570 nm, 650 nm, 1344 nm, 1462 nm, 1863 nm, 2647 nm, 3033 nm, 3041 nm, 3805 nm, 3991 nm and 8109 nm) 4 relates to data on metal oxide films having film thicknesses (334 nm, 570 nm, 650 nm, 1344 nm, and 3033 nm).

The first and second heat treatments are heating at a temperature (for example, 300 DEG C or less) at which the change in crystallinity of the metal oxide film (oxygen vacancy of ZnO, etc. is not caused) In the first and second heat treatments shown in Figs. 3 and 4, the metal oxide film was heated at 200 캜.

The deposited metal oxide film (ZnO: zinc oxide film) used in the experiment was formed (film-formed) by the above-described process using the apparatus shown in Fig. Here, the heating temperature of the substrate 1 during film formation is 200 占 폚, the supply amount of the solution 5 containing zinc (Zn) is 0.7 to 0.8 mmol / min, the supply amount of water as the oxidizing source 6 is, 44 to 89 millimoles per minute. The concentration of zinc in the solution 5 containing zinc is 0.35 mol / liter.

The metal oxide film formed under the non-vacuum has a higher resistivity than the metal oxide film formed under vacuum. As shown in the experimental data shown in Figs. 3 and 4, it was found that the resistivity of the metal oxide film was lowered by irradiating the metal oxide film formed under the non-vacuum state with ultraviolet light.

It is also understood from Figs. 3 and 4 that when the heat treatment is performed, the resistivity of the metal oxide film having the resistivity lowered increases. It is also understood from Figs. 3 and 4 that the resistivity raised by the heat treatment by ultraviolet irradiation can be lowered again.

Therefore, in the case where the metal oxide film having a high resistance formed under a non-vacuum state is irradiated with ultraviolet light, and the metal oxide film has a high resistance due to the heating step, the metal oxide film after the heating step is irradiated with ultraviolet light, This is effective from the viewpoint of lowering the resistance of the metal oxide film. Here, even when the heating process (heat treatment) and the ultraviolet ray irradiation process are repeatedly performed on the metal oxide film, the resistance increased by the heat treatment can be reduced after the ultraviolet ray irradiation process.

3 and 4, the inclination indicating the decrease in the resistivity of the metal oxide film when the ultraviolet ray having the center wavelength of 254 nm is irradiated (referred to as the first ultraviolet ray) after the first heat treatment, Attention is drawn to a slope indicating a decrease in the resistivity of the metal oxide film when ultraviolet rays of 365 nm (referred to as a second ultraviolet ray) are irradiated.

Thus, for a metal oxide film having a relatively thin film thickness, the resistivity of the metal oxide film can be greatly reduced in a short time, as compared with the case of the second ultraviolet ray irradiation, by the first ultraviolet ray irradiation. On the other hand, with respect to the metal oxide film having a relatively large film thickness, the resistivity of the metal oxide film can be greatly reduced in a short time in the second ultraviolet ray irradiation than in the first ultraviolet ray irradiation.

That is, from the viewpoint of efficient low resistance, it is effective to select and determine the optimum wavelength of the ultraviolet ray to be irradiated in response to the film thickness of the metal oxide film.

Specifically, as the film thickness of the metal oxide film becomes thick, it is preferable to select a film having a large value as the wavelength of ultraviolet ray from the viewpoint of efficient low resistance. This is because the depth of penetration of the ultraviolet ray into the metal oxide film is proportional to the wavelength of the ultraviolet ray.

That is, the entry depth d of light is represented by d = 1 / ?. Here,? Is an absorption coefficient and? = 4? K /? (K: extinction coefficient,?: Wavelength). That is, the penetration depth of the ultraviolet rays into the metal oxide film is proportional to the wavelength of the ultraviolet ray. (The larger the wavelength of the ultraviolet ray, the more intruded the ultraviolet rays can penetrate to the deeper position of the metal oxide film.

Therefore, unless the ultraviolet ray having a larger wavelength is used as the metal oxide film having a thicker film thickness, ultraviolet rays are not irradiated to the entire film thickness direction of the thicker metal oxide film and the efficiency of lowering the resistance of the metal oxide film . Therefore, from the viewpoint of efficient low resistance, it is preferable that the wavelength of the ultraviolet ray to be determined is increased proportionally as the film thickness of the metal oxide film becomes thick.

When the wavelength of the ultraviolet ray is larger than 380 nm, the metal oxide film (zinc oxide film) does not absorb the ultraviolet ray. Therefore, for the zinc oxide film, the wavelength of the ultraviolet ray to be irradiated needs to be 380 nm or less.

In addition, a light source that emits ultraviolet rays having a wavelength of 254 nm and an ultraviolet ray that emits a wavelength of 365 nm are available at relatively low cost. Therefore, it is very advantageous to find out which one of the wavelengths of 254 nm and 365 nm is selected in accordance with the film thickness of the metal oxide film for more efficient low resistance.

5 is a table showing which of the wavelengths of 254 nm and 365 nm is advantageous for the ultraviolet ray to be irradiated according to the film thickness of the metal oxide film. Here, FIG. 5 is created by using the data shown in FIG.

The uppermost column in FIG. 5 is a film thickness (259 nm, 303 nm, 334 nm, 374 nm, 570 nm, 650 nm, 1344 nm, 1462 nm, 1863 nm, 2647 nm, 3033 nm, 3041 nm, 3805 nm, 3991 nm and 8109 nm) of the metal oxide film. 5 shows the irradiation time of ultraviolet rays (1 minute, 5 minutes, 10 minutes, 30 minutes, 60 minutes).

The numerical values of the respective columns in Fig. 5 are (resistivity of metal oxide film after irradiation time with irradiation of ultraviolet ray having a center wavelength of 254 nm) / (resistivity of metal after elapse of irradiation time when ultraviolet ray having a central wavelength of 365 nm was irradiated) The resistivity of the oxide film).

For example, attention is paid to the third column of FIG. 5 (the film thickness is 303 nm). The value of the second row of the third column (the row for one minute of irradiation with ultraviolet rays) is a value obtained by dividing the resistivity of the metal oxide film after irradiation by the ultraviolet ray having a center wavelength of 254 nm for one minute with respect to the metal oxide film having a film thickness of 303 nm Quot; is a value obtained by dividing the metal oxide film having a film thickness of 303 nm by the resistivity of the metal oxide film after irradiation with ultraviolet light having a center wavelength of 365 nm for 1 minute ", and the value is " 0.8 ".

Note that, for example, attention is paid to the seventh column (the film thickness of 650 nm) in Fig. The value of the fifth row of the 7th row (the row of 30 minutes of ultraviolet irradiation) was calculated as follows: when the ultraviolet ray having a center wavelength of 254 nm was irradiated to the metal oxide film having a film thickness of 650 nm for 30 minutes, the resistivity of the metal oxide film after the irradiation Quot; is a value obtained by dividing the metal oxide film having a film thickness of 650 nm by the resistivity of the metal oxide film after irradiation with ultraviolet light having a center wavelength of 365 nm for 30 minutes ", and the value is " 2.6 ".

In the following description, the resistivity of the metal oxide film after irradiation with ultraviolet light having a center wavelength of 254 nm / resistivity of the metal oxide film after irradiation with ultraviolet light having a center wavelength of 365 nm is set to " Resistivity comparison ratio ".

Here, when the resistivity comparison ratio is smaller than "1", the resistance of the metal oxide film can be lowered more efficiently than when irradiated with ultraviolet rays having a center wavelength of 254 nm, as compared with irradiation of ultraviolet light having a center wavelength of 365 nm it means. In other words, when the resistivity comparison ratio is larger than "1", the resistance of the metal oxide film can be lowered more efficiently than when the ultraviolet ray having a center wavelength of 254 nm is irradiated with ultraviolet light having a center wavelength of 365 nm .

5, when a metal oxide film having a film thickness of 570 nm or less is irradiated with ultraviolet rays having a center wavelength of 254 nm, the film thickness of the metal oxide film is lowered more effectively than when the ultraviolet ray having a center wavelength of 365 nm is irradiated, Can be realized.

This is shown more clearly in Fig. 6 (vertical axis: resistivity (Ω · cm), transverse axis: ultraviolet ray irradiation time (minute)), a metal oxide film having a thickness of 570 nm was irradiated with an ultraviolet ray having a center wavelength of 254 nm and a change in resistivity, And ultraviolet ray irradiation and change in resistivity are shown. As shown in Fig. 6, in the case of a metal oxide film having a film thickness of 570 nm, when the ultraviolet ray having a center wavelength of 254 nm is irradiated, the resistance of the metal oxide film is lowered more efficiently than when the ultraviolet ray having a center wavelength of 365 nm is irradiated .

On the other hand, in the case of the metal oxide film having a film thickness of at least 650 nm, on the other hand, the table in FIG. 5 shows that the film when irradiated with ultraviolet rays having a center wavelength of 365 nm is more efficiently irradiated with ultraviolet rays having a center wavelength of 254 nm It can be understood that the resistance can be reduced.

This is shown more clearly in Fig. In the case of a metal oxide film having a film thickness of 650 nm, ultraviolet ray irradiation with a center wavelength of 254 nm and change in resistivity and change in resistivity and center wavelength to 365 nm (resistivity (Ω · cm) and transverse axis And ultraviolet ray irradiation and change in resistivity are shown. As shown in Fig. 7, in the case of a metal oxide film having a film thickness of 650 nm, when the ultraviolet ray having a center wavelength of 365 nm is irradiated, the resistance of the metal oxide film is lowered more efficiently than when the ultraviolet ray having a center wavelength of 254 nm is irradiated .

It is also possible to utilize the fact that the resistivity comparison ratio linearly increases between the film thickness of 570 nm and 650 nm from the data of the sixth column of FIG. 5 (film thickness = 570 nm) and the data of the seventh column of FIG. 5 And an average value was calculated. As a result, it was found that the resistivity comparison ratio became "1" when the film thickness of the metal oxide film was about 590 nm.

For example, when linearly increasing the resistivity comparison ratio between 570 nm and 650 nm is used, when the ultraviolet irradiation is for 1 minute, the film thickness of the metal oxide film having the resistivity comparison ratio of " 1 " , The film thickness of the metal oxide film having the resistivity comparison ratio of " 1 " is " 583 nm " when the ultraviolet irradiation is 5 minutes, and the film thickness of the metal oxide film When the thickness of the metal oxide film is " 596 nm ", and when the ultraviolet irradiation is performed for 30 minutes, the film thickness of the metal oxide film having the resistivity comparison ratio of 1 is " 586 nm & The film thickness of the metal oxide film is " 607 nm ". By the average value of these film thicknesses, it was found that the resistivity comparison ratio becomes "1" when the film thickness of the metal oxide film is about 590 nm.

That is, the inventors of the present invention have found that when a metal oxide film having a film thickness of less than 590 nm is irradiated with ultraviolet light having a center wavelength of 254 nm, the resistance of the metal oxide film can be more efficiently reduced than when ultraviolet light having a center wavelength of 365 nm is irradiated .

Further, the inventors of the present invention have found that when a metal oxide film having a film thickness of 590 nm or more is irradiated with ultraviolet light having a center wavelength of 365 nm, the resistance of the metal oxide film can be lowered more efficiently than when ultraviolet light having a center wavelength of 254 nm is irradiated .

Further, in the case of a metal oxide film having a film thickness of 590 nm, it is considered that the resistance of the metal oxide film can be reduced to the same level of efficiency even when ultraviolet rays having a center wavelength of 254 nm are irradiated or ultraviolet rays having a center wavelength of 365 nm are irradiated .

Therefore, when determining the ultraviolet ray to be irradiated to the metal oxide film, a wavelength including at least 254 nm is selected when the film thickness of the metal oxide film is smaller than 590 nm, and when the film thickness of the metal oxide film is larger than 590 nm, It is preferable from the viewpoints of lowering the cost of ultraviolet irradiation and improving the efficiency of reducing the resistance.

In addition, from the viewpoints of lowering the resistance of the metal oxide film by irradiating ultraviolet rays to the metal oxide film after the film formation and the heat treatment after the film formation, the film thickness of the metal oxide film , The wavelength of the ultraviolet ray to be irradiated is selected and determined) is confirmed both in the case where the dopant is contained in the metal oxide film and the case where the dopant is not contained in the metal oxide film. Further, even when the dopant is contained in the metal oxide film, it is confirmed that the contents of the above description are satisfied without depending on the kind of the dopant such as boron or indium.

As described above, in the method for producing a metal oxide film according to the present embodiment, the solution 5 containing zinc is made into a mist, and the mist 5 is sprayed onto the substrate 1 under a non- The metal oxide film 10 is formed on the substrate 1 (Fig. 1). Then, the metal oxide film 10 is irradiated with an ultraviolet ray 13 (Fig. 2).

Therefore, even if the metal oxide film is formed on the substrate 1 under non-vacuum and the resistance of the metal oxide film thus formed becomes high resistance, the resistance of the metal oxide film can be lowered by the subsequent ultraviolet irradiation (vacuum The resistance of the metal oxide film formed under the non-vacuum can be reduced to the same level as the resistance of the metal oxide film formed under the non-vacuum state).

Further, in the method of manufacturing a metal oxide film according to the present embodiment, since it is not necessary to employ a vacuum apparatus or the like as a manufacturing (film forming) apparatus (that is, a film forming process under a non-vacuum condition), the cost can be reduced, .

In the method for producing a metal oxide film according to the present embodiment, the wavelength of the ultraviolet ray to be irradiated is determined according to the film thickness of the metal oxide film. For example, as the film thickness of the metal oxide film becomes thick, a film having a large value as the wavelength of the ultraviolet ray is selected.

Therefore, it is possible to irradiate the metal oxide film with ultraviolet rays having a wavelength that enables high efficiency of the low resistance (the resistivity is further reduced in a short time) in accordance with the film thickness of the metal oxide film.

In the method of manufacturing a metal oxide film according to the present embodiment, when the film thickness of the metal oxide film is smaller than 590 nm, a wavelength including at least 254 nm is selected and determined. When the film thickness of the metal oxide film is larger than 590 nm , A wavelength including at least 365 nm may be selected and determined.

An ultraviolet light source having a wavelength of 254 nm and an ultraviolet light source having a wavelength of 365 nm are inexpensive. Ultraviolet rays capable of achieving a low resistance with high efficiency are selected according to the film thickness of the metal oxide film. Therefore, in the method of manufacturing a metal oxide film according to the present invention for selecting and determining the wavelength, it is possible to achieve a low-resistance high-efficiency and a low manufacturing cost of the metal oxide film.

In the method of manufacturing a metal oxide film according to the present embodiment, ultraviolet irradiation may be performed after forming the metal oxide film to lower the resistance of the metal oxide film. However, by performing the heat treatment after film formation, The metal oxide film may be irradiated with ultraviolet rays to reduce the resistance of the metal oxide film having a high resistance.

Here, when it is necessary to perform the heat treatment for the metal oxide film a plurality of times, the ultraviolet ray irradiation treatment may be performed after each heating treatment, or a plurality of heat treatments may be performed, and ultraviolet ray irradiation treatment may be performed once . In addition, it is preferable that the selection and determination of the wavelength when ultraviolet irradiation is performed from the viewpoint of high efficiency and low resistance as described above.

It is sometimes desired in the manufacturing process to perform the heat treatment at least once on the metal oxide film after the metal oxide film is formed. Even in this case, by performing the ultraviolet ray irradiation after the heat treatment, the resistance of the metal oxide film becoming high resistance can be reduced. Further, by selecting and determining the wavelength at the time of irradiation with the ultraviolet ray to a predetermined value, and irradiating the ultraviolet ray having the selected and determined wavelength to the metal oxide film having a high resistance, the metal oxide film has high efficiency and low resistance.

While the invention has been described in detail, the foregoing description is, in all aspects, illustrative and not restrictive. It is understood that a myriad of variations not illustrated may be made without departing from the scope of the present invention.

1: substrate
2: heater
3A, 3B: container
4A, 4B: atomizer
5: solution
6: Oxidation circle
8: Nozzle
10: Metal oxide film (transparent conductive film, zinc oxide film)
12: UV lamp
13: ultraviolet ray
L1, L2: path

Claims (5)

(A) forming a metal oxide film on the substrate by mistating a solution containing zinc and spraying the misted solution onto the substrate under a non-vacuum condition;
(B) a step of lowering the resistance of the metal oxide film by irradiating the metal oxide film with ultraviolet light,
The step (B)
(B-1) a step of determining the wavelength of the ultraviolet ray to be irradiated in accordance with the film thickness of the metal oxide film,
(B-2) a step of irradiating the metal oxide film with the ultraviolet ray having a wavelength determined in the step (B-1)
The step (B-1)
Wherein a larger value of the wavelength of the ultraviolet ray is selected as the film thickness of the metal oxide film becomes thicker. The method according to claim 1,
The step (B-1)
And when the film thickness of the metal oxide film is smaller than 590 nm, the wavelength including at least 254 nm is selected. The method according to claim 1,
The step (B-1)
And when the film thickness of the metal oxide film is larger than 590 nm, the wavelength including at least 365 nm is selected. The method according to claim 1,
(C) heating the metal oxide film,
The step (B)
Wherein the step (C) is performed after the step (C). A metal oxide film produced by the method for producing a metal oxide film according to any one of claims 1 to 4.

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